The invisible nanoparticles (NP)*) from combustion processes penetrate easily into the human body through the respiratory and olfactory pathways and carry numerous harmful health effects potentials.
NP count concentrations are limited in EU for Diesel passenger cars since 2013 and for gasoline cars with direct injection (GDI) since 2014. The limit for GDI was temporary extended to 6 × 1012 #/km, (regulation No. 459/2012/EU).
Nuclei of metals as well as organics are suspected to significantly contribute especially to the ultrafine particle size fractions, and thus to the particle number concentration.
In the project GasOMeP (Gasoline Organic & Metal Particulates) metal-nanoparticles (including sub 20nm) from gasoline cars are investigated for different engine technologies.
In the present paper some results of investigations of nanoparticles from four gasoline cars - an older one with MPI and three newer with DI - are represented. The measurements were performed at vehicle tailpipe and in CVS-tunnel.
The results show that the older vehicle with MPI emits high particle count concentrations. The size distributions of this vehicle are decisively bimodal with high numbers in nuclei mode.
The emissions of the newer vehicles with DI show sometimes no typical uniform shape of particle size distributions and are at lower level, than for the older vehicle. There is no visible nuclei mode and the ultrafine particle concentrations below 10nm are insignificant.
A size-selective analysis of the composition of NP's in NEDC revealed an increased amount of Na, Mg, Ca & Zn in the lowest size range, below 100nm.
Some of the newer, low-emitting vehicles show at constant speed operation a periodical fluctuation of the NP-emissions.
Increased NP-emissions at cold start were confirmed.